“We will be the first G8 country to do so,” she said. “It is in everyone's interests for countries around the world to be stable and secure, to have educated and healthy populations, and to have growing economies."

The news comes after Tory MPs criticised the Government for announcing £1.8 billion of spending on foreign climate change projects on the eve of the Autumn Statement.

The Conservatives, including Lord Lawson of Blaby, the former chancellor, said the aid going towards subsidies for wind farms in Africa, greener cattle farms in Colombia and other projects was "an appalling waste of money".